QRP operation—low-power HF communications—is at the heart of most of my field radio deployments. It’s efficient, man-portable, and power-friendly. But there are moments when 5 to 10 watts just isn’t enough. In real-world emergencies, when our messages fail to get through, output power becomes a tool—not a luxury.
That’s the topic of today’s video: When QRP Is Not Enough. I’ll walk you through a real-world field scenario where a Winlink session fails to connect, despite ideal setup. The problem? Propagation isn’t playing along. The solution? Selectively scaling up our capabilities.
Watch the video:
When Conditions Fail, So Could QRP
During poor propagation, even the best QRP setup has its limits. Solar conditions can deminishn our chances of being heard. The target station might be too far for NVIS to reach, or too close for skip to carry. Urban RF noise, elevation changes, or just bad timing can all turn a reliable 10-watt station into a whisper no one hears.
In those moments, low power stops being a point of pride and becomes a liability. That’s when having an HF amplifier in the field kit becomes more than just a convenience—it becomes a lifeline.
Before you crank up the power
Before you start warning the atmosphere, there are a few things you should have tried first.
- Did you try to change over to a WARC band?
- Did you try a narrower mode RPR, 500hz VarAC, JS8Call?
- Did you ensure your antenna configurations was ideal for your targeted station?
- Did you try a more efficient antenna?
These questions are foundational! Too often operators are too lazy to put in the work, because ramping up the power is so much easier. The things is, if we default in ramping up power, we never learn how to optimaze for station efficiency.
Choosing the Right HF Amplifier for Field Work
Not all amplifiers are created equal—and most are designed for fixed stations with reliable grid power. For field or emergency use, the criteria can shift dramatically. Keep in mind, my choices almost always ignore the price, and focus specifically on efficiency, weight, and size. Therefore, my ideal amplifier should have:
- Low current draw on RX & TX – to avoid draining your battery reserves
- Compact and lightweight – so it actually fits in a backpack or go-kit
- Rugged – able to survive knocks, moisture, and transport
- Voltage-flexible – capable of running on 11–15V DC (perfect for LiFePO₄ setups)
- Efficient – no massive heatsinks or wasted energy
- Optional extras – like a built-in antenna tuner or PTT sensing help simplify field use
My Pick: The DL4KA PA500
In the video, I introduce my amplifier of choice: the PA500 from DL4KA. It checks all the boxes:
Lightweight and highly compact Runs cleanly off 12V battery systems Reasonable current draw for field deployment High build quality designed for rugged environments Optional features for smart integration
Although I don’t always use it, I do carry it on most excursions. It lives in my “expanded HF kit”, deployed only when QRP proves insufficient or when I know conditions will be marginal. Think: poor propagation, distant Winlink RMS stations, or critical messages that can’t afford to get lost in the noise.
QRP Is Still the Foundation
I want to be clear: I’m not abandoning QRP. It’s still the foundation of my field communications—especially for its efficiency, reduced energy demands, and tactical discretion. But flexibility is key. When the grid is down and the stakes are high, the ability to push 50–100 watts (as needed) through a proven setup can mean the difference between silence and successful coordination.
This video isn’t about abandoning QRP—it’s about knowing when to scale up.
Watch the full video above and let me know: Do you carry an amp in your field kit? Why or why not?
Here was the first video shared on the channel about the PA500:
73
Julian OH8STN
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